Purpose To evaluate the diagnostic performance of gray-scale ultrasonography (US) and elastography in differentiating benign and malignant thyroid nodules. Materials and methods This was an institutional review board-approved retrospective study with waiver of informed consent. A total of 703 solid thyroid nodules in 676 patients (mean age, 49.7 years; range, 18-79 years) were included; there were 556 women (mean age, 49.5 years; range, 20-74 years) and 120 men (mean age, 50.7 years; range, 18-79 years). Nodules with marked hypoechogenicity, poorly defined margins, microcalcifications, and a taller-than-wide shape were classified as suspicious at grayscale US. Findings at elastography were classified according to the Rago criteria and the Asteria criteria. The diagnostic performances of gray-scale US and elastography were compared. For comparison between the diagnostic performances of gray-scale US and the combination of gray-scale US and elastography, three sets of criteria were assigned: criteria set 1, nodules with any suspicious grayscale US feature were assessed as suspicious; criteria set 2, Rago criteria were added as suspicious features to criteria set 1; and criteria set 3, Asteria criteria were added as suspicious features to criteria set 1. The diagnostic performances of gray-scale US, elastography with Rago criteria, and elastography with Asteria criteria, and odds ratios (ORs) with 95% confidence intervals for predicting thyroid malignancy were compared using generalized estimating equation analysis. Results Of 703 nodules, 217 were malignant and 486 were benign. Sensitivity, negative predictive value (NPV), and OR of gray-scale US for the 703 nodules were 91.7%, 94.7%, and 22.1, respectively, and these values were higher than the 15.7% and 65.4% sensitivity, 71.7% and 79.1% NPV, and 3.7 and 2.6 ORs found for elastography with Rago and Asteria criteria, respectively. Specificity, positive predictive value, and accuracy for criteria set 1 were significantly higher than those for criteria sets 2 and 3 for most of the nodule subgroups that were considered. Conclusion Elastography alone, as well as the combination of elastography and gray-scale US, showed inferior performance in the differentiation of malignant and benign thyroid nodules compared with gray-scale US features; elastography was not a useful tool in recommending fine-needle aspiration biopsy.

https://ir.ymlib.yonsei.ac.kr/bitstream/22282913/91777/1/T201200373.pdf

Diagnostic performance of gray-scale US and elastography in solid thyroid nodules

This paper presents a pico-ampere voltage reference for IoT systems with high performance in line regulation and power supply rejection ratio (PSRR). Based on the leakage current characteristics of MOSFETs, the reference voltage is obtained by taking advantage of the threshold voltage differences between two types of MOSFETs with different gate oxide thicknesses. By employing a self-regulation technique, the impacts of drain-induced barrier lowering (DIBL), gate-induced drain leakage (GIDL) and gate-drain capacitance feedthrough effects can be mitigated, resulting in high performance in line regulation and PSRR. Based on a 0.18 μm standard CMOS process, post-layout simulation results show the temperature coefficient is 28.0 ppm/°C over the temperature range of 0–120 °C with a 0.6 V supply voltage. The line regulation is 2.54 ppm/V, which is at least two orders of magnitude lower than existing designs in the literature. The PSRR is −77 dB@100 Hz that is improved by at least 10 dB over existing designs in the literature.

A 28 ppm/°C, 2.54 ppm/V, −77 dB@100 Hz pico-ampere voltage reference for high-end IoT systems

Background Thyroid nodules are frequent in adult population and thyroid cancer incidence has increased dramatically over the past three decades. The aim of this systematic review and meta-analysis was to evaluate the US-Elastosonography (USE) diagnostic performance in assessing the thyroid nodules malignancy risk. Methods PubMed and Embase databases were searched from January 2011 to July 2021. We extracted data from selected studies and calculated the overall diagnostic accuracy of qualitative USE, semi-quantitative USE and quantitative USE. Summary receiver operating characteristic (ROC) curve was elaborated to show the results. All statistical tests were performed using Metadisc and Medcal software package. Results Finally 72 studies with 13,505 patients and 14,015 thyroid nodules (33% malignant) undergoing elastography were included. The pooled sensitivity, specificity and AUC were 84%, 81%, and 0.89 respectively for qualitative USE; 83%, 80%, and 0.93 for semi-quantitative USE and 78%, 81% and 0.87, for quantitative USE. The qualitative and semiquantitative USE present very similar diagnostic accuracy values and both better than the quantitative USE. Conclusions USE is a useful imaging tool for thyroid nodule characterization. In accordance with recent guidelines and meta-analyses, the USE could be used daily in thyroid nodule malignancy risk stratification. Systematic Review Registration PROSPERO: CRD42021279257.

/pdf/us-elastography-with-different-techniques-for-thyroid-nodule-13jux9xj.pdf

US-Elastography With Different Techniques for Thyroid Nodule Characterization: Systematic Review and Meta-analysis

Objective This study aims to evaluate the clinical value of ultrasound elastography (USE) in providing information on the nature of the thyroid nodules. This was performed using the elastography score and strain ratio in differentiating thyroid benign and malignant nodules and the histopathological examination was used as the diagnostic standard of reference. Methods We examined 84 thyroid nodules in 62 patients with ultrasound elastography. Elastography score was assigned based on a four-point scale according to the classification proposed by Itoh et al. with a score of 1 (low stiffness over the entire nodule) to a score of 4 (high stiffness over the entire nodule). Thyroid strain ratio (normal tissue to lesion strain ratio) was calculated. Histopathological results were the standard reference. The area under the curve (AUC) and the best cut-off point were both obtained using receiver-operating characteristic (ROC) curve analysis. The sensitivity, specificity, and accuracy of both techniques were calculated. Results Fifty-four of the 84 nodules had scores of 1 and 2, and 50 of these nodules were diagnosed histopathologically as benign. Thirty of the 84 nodules had a score of 3 and 4, and 21 of these nodules were diagnosed histopathologically as malignant. The scores of 1 and 2 with Itoh criteria were significantly seen in benign nodules, whereas, scores of 3 and 4 were significantly seen in malignant nodules ( p p Conclusions Both the elastographic score and strain ratio are higher in malignant nodules than those in benign ones. Ultrasound elastography can provide quantitative information on thyroid nodule helping in differentiating benign and malignant ones.

The clinical value of ultrasound elastography in predicting malignant thyroid nodules

This paper grants implementation and design of Bandgap reference circuit with 0.2ppm/ low temperature coefficient in 180nm CMOS process technology. The designed circuit achieves a simulated output voltage reference of 1.12V at room temperature (27°C) with the temperature range of −40°C to +125°C under supply voltage of 1.8V. The power consumption is 52.37uW at room temperature and active area is 81.4um∗63.43um. The designed circuit was implemented using Cadence Virtuoso and simulated using Spectre ADE.

Design of an improved bandgap reference in 180nm CMOS process technology

This paper presents a high wide band power supply rejection ratio (PSRR) current mode bandgap reference (BGR) with a fast startup performance. The BGR includes three main enhancement techniques to improve the PSRR. The proposed design is implemented in 130nm CMOS technology. It only consumes 50μA from a 1.8V supply. The BGR provides 850mV reference voltage and has a power supply rejection ratio (PSRR) of 130dB from DC to 100Hz and more than 110dB till 100MHz. The temperature coefficient (TC) is 10 ppm/°C from −40°C to 125° C. The Bandgap start-up time is 70ns.

A high wide band PSRR and fast start-up current mode bandgap reference in 130nm CMOS technology

Background Solitary thyroid nodule may represent a multitude of thyroid disorders; therefore, detection of whether these nodules are benign or malignant is crucial for patient’s triage. Objective To evaluate the diagnostic performance of the latest generation of real-time ultrasound elastography (USE) in differentiation between benign and malignant solitary thyroid nodules. Materials and methods Thirty consecutive patients who were referred for surgical treatment were prospectively examined by real-time USE. Tissue stiffness on real-time USE was determined with light compression using the standard elastography color scoring system according to Rago criteria ranging from 1 (low stiffness over the entire nodule) to 5 (high stiffness over the entire nodule and surrounding tissue). The strain ratio (normal tissue to lesion strain ratio) was calculated. The histopathological examination of these resected nodules was used as the diagnostic standard of reference. Results Scores of 1 and 2 with Rago criteria were highly significant seen in benign nodules, whereas, scores of 4 and 5 with Rago criteria were highly significant seen in malignant nodules (p  Conclusion Both the color score and the strain ratio are higher in malignant solitary thyroid nodules than those in benign ones. Consequently, real-time USE can be used for the differentiation of benign and malignant solitary thyroid nodules. Eventually, this reduces the number of superfluous surgical procedures on benign thyroid nodules.

Can real-time ultrasound elastography using the color score and strain ratio differentiate between benign and malignant solitary thyroid nodules?

This paper presents an ultra-low quiescent current bandgap reference. The BGR is based on a resistor-less topology to reduce area and current consumption. The proposed design was implemented in TSMC 130-nm CMOS technology. It only consumes 1.6 nA from a 1.8-V supply. The BGR provides about 770-mV reference voltage and has power supply rejection ratio (PSRR) of 57 dB at DC. The temperature coefficient (TC) is 5 ppm/°C from −40 to 125 °C. Process variation and mismatches are kept as low as 1.4% per sigma.

Amr Kamel

Papers

A high wide band PSRR and fast start-up current mode bandgap reference in 130nm CMOS technology

Can real-time ultrasound elastography using the color score and strain ratio differentiate between benign and malignant solitary thyroid nodules?

A 1.6-nA quiescent current bandgap reference in 130-nm CMOS technology